Changes in pulse waveforms in response to intraocular pressure elevation determined by laser speckle flowgraphy in healthy subjects.

BACKGROUND: The influences of intraocular pressure (IOP) elevations on the pulse waveform in the optic nerve head (ONH) were evaluated using laser speckle flowgraphy (LSFG) in normal subjects. METHODS: This prospective cross-sectional study was conducted at the Nagoya University Hospital. An ophthalmodynamometer was pressed on the sclera to increase the IOP by 20 mmHg or 30 mmHg for 1 min (experiment 1, 16 subjects) and by 30 mmHg for 10 min (experiment 2, 10 subjects). The mean blur rate (MBR) and the eight pulse waveform parameters determined using LSFG were measured before, immediately after and during an IOP elevation, and after the IOP returned to the baseline pressure. RESULTS: A significant elevation in the IOP and a significant reduction in the ocular perfusion pressure (OPP) were found after applying the ophthalmodynamometer (both, P < 0.001). The blowout score (BOS) reduced significantly (P < 0.001), and the flow acceleration index (FAI; P < 0.01) and resistivity index (RI; P < 0.001) increased significantly immediately after increasing the IOP by 20 or 30 mmHg (experiment 1). The BOS reduced significantly (P < 0.001), and the FAI (P < 0.01) and RI (P < 0.001) increased significantly after the IOP elevation by 30 mmHg in both experiment 2 and 1. However, the BOS and RI recovered significantly at time 10 compared to that in time 0 (immediately after IOP elevation) during the 10-min IOP elevation (P < 0.001 and P = 0.008, respectively). CONCLUSIONS: In conclusion, the BOS, FAI, and RI of the pulse waveforms changed significantly with an acute elevation in the IOP. The change should be related to the larger difference between the maximum and minimum MBRs during the IOP elevation.

Investigation of causative factors for unusual shape of macula in eyes with macula-off rhegmatogenous retinal detachment.

PURPOSE: To determine the factors significantly associated with anterior protrusion of the macula in eyes with a macula-off rhegmatogenous retinal detachment (RRD) and to determine the relationship between the intraretinal cystoid cavities (ICCs) and the anterior protrusion and function of the fovea. STUDY DESIGN: Retrospective cross-sectional study. METHODS: Sixty-nine eyes of 69 patients with successfully reattached macula-off RRD were retrospectively analyzed. Six radial spectral-domain optical coherence tomographic (OCT) images were used to evaluate the effects of the ICCs on detached macula and to measure the angle of the retina at the macula as a parameter to evaluate the anterior protrusion of the detached retina. The findings were compared to other parameters. RESULTS: The mean angle of the retina at the macula was 143.1 ± 15.9° with a range of 108 to 172°. Preoperatively, 51 eyes (74%) had ICCs in the inner nuclear layer and/or the outer plexiform layer and Henle fiber layer complex, but none was present after surgery. Multivariate regression analyses revealed that the angle of the retina was significantly associated with the presence of ICCs (ß = -0.637, P<0.001) and the height of subretinal fluid (ß = -0.256, P = 0.005). Eyes with ICCs had poorer preoperative vision (P<0.001), narrower angle of the retina (P<0.001), and thicker subretinal fluid (P<0.001) than eyes without cavities. CONCLUSIONS: The anterior protrusion in eyes with macula-off RRD is associated with the presence of ICCs. The presence of ICCs can affect preoperative function and morphology but does not affect postoperative function and morphology.